Analogue filters minimise distortion

February 16, 2016 // By Susan Nordyk
The D68 series of 8-pole analogue filters from Frequency Devices exhibits THD (total harmonic distortion) levels as low as -100 dB with near-theoretical frequency response.

Offered in low-pass and high-pass versions with Butterworth, Bessel, elliptic, and constant-delay transfer functions, the D68 series provides linear active filtering in a small 32-pin DIP package.

Each model comes factory-tuned to a user-specified corner frequency between 1 Hz and 100 kHz. Units can be combined to create custom band-pass or band-reject filters. The self-contained devices require no external components or adjustments and operate over a wide dynamic input voltage range from noncritical ±5-V to ±18-V power supplies.

Filters in the D68 series have dimensions of 1.8×0.8×0.3 inches, conserving board space in a broad range of applications, including anti-aliasing filtering, data-acquisition systems, communications equipment, and medical electronics. They are also suitable for sound and vibration testing, acoustic and vibration control, and signal reconstruction.

D68 series product page

Frequency Devices,